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Jun 12 MS.pdf


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Mark Scheme – General Certificate of Education (A-level) Chemistry – Unit 1: Foundation Chemistry – June 2012

Question
1(a)

Marking Guidance

Mark

Comments

37

1

48

1

Electron gun / high speed/high energy electrons

1

Not just electrons.
Not highly charged electrons.

Knock out electron(s)

1

Remove an electron.

Rb(g) → Rb+(g) + e(-)
OR
Rb(g) + e(-) → Rb+(g) + 2e(-)
OR
Rb(g) - e(-) → Rb+(g)

1

Ignore state symbols for electron.

Rb is a bigger (atom) / e further from nucleus / electron
lost from a higher energy level/ More shielding in Rb /
less attraction of nucleus in Rb for outer electron / more
shells

1

Answer should refer to Rb not Rb molecule.
If converse stated it must be obvious it refers to Na
Answer should be comparative.

1(d)(i)

s / block s / group s

1

Only

1(d)(ii)

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1

1

Allow 3d10 before 4s2
Allow in any order.

1(b)(i)

1(b)(ii)

1(c)

3

These answers only.
Allow answers in words.
Ignore any sum(s) shown to work out the answers.